A senior staff member at the University of Zimbabwe has been suspended for allegedly procuring academic caps for Mugabe that were too small for his head, according to court papers filed this week.

A mortarboard that was offered to the long-time leader at a graduation ceremony last year was rejected as too small, the papers said. But Mugabe wore that same mortarboard without any problems at an October 2 ceremony after the cap bought for this year was also rejected as tiny, they said.

Mugabe appeared at the ceremonies in his role as chancellor of Zimbabwe's dozen-plus state universities.

Ngaatendwe Takawira, an assistant registrar at the University of Zimbabwe, has approached the labour court to try to stop disciplinary hearings against her over the cap mishap.

The university alleges that this year's graduation ceremony had to be delayed by 45 minutes while authorities cast around for a cap that fit Mugabe.

Ms Takawira has argued that, after efforts to get a replacement failed, the 91-year-old leader wore a previously rejected cap that was the right size.

"It fit the chancellor perfectly well," she said in the papers, filed by her lawyer Thabani Mpofu.

"The cap sizes were obtained from the chancellor's office and also, when he was asked to fit the caps, his office indicated that he was busy," she said.

Ms Takawira, who said she has been in charge of the university's graduation ceremonies since 1996, wants the labour court to stop what she calls "biased" disciplinary hearings against her and allow an independent committee to conduct the proceedings.

The university has said there is no evidence of bias on the disciplinary committee handling the case.